TWI808459B - Plasma treatment device and manufacturing method of gas spray ring thereof - Google Patents

Abstract

The invention discloses a plasma processing device and a method for making a gas spray ring thereof. The plasma processing device comprises: a vacuum reaction chamber; an upper electrode assembly located at the top of the vacuum reaction chamber; a lower electrode assembly located at the bottom of the vacuum reaction chamber. A plasma is generated between the assembly and the lower electrode assembly. The advantages of the present invention are: the plasma processing device realizes the delivery of the reaction gas through the gas spray ring, and the uneven delivery of the reaction gas will not affect the etching effect due to the installation error of the upper electrode assembly, etc., which greatly improves the use stability of the plasma treatment device.

Description

Plasma treatment device and manufacturing method of gas spray ring thereof

The invention relates to the field of semiconductor equipment, in particular to a plasma treatment device and a method for manufacturing the gas spray ring.

In the manufacturing process of semiconductor devices, plasma etching is a key process for processing wafers into design patterns. During the entire wafer processing process, the cleaning of the upper electrode assembly and the vacuum reaction chamber of the plasma processing device, as well as the uniformity of the reaction gas and plasma environment have a great impact on the etching effect of the wafer.

In the existing plasma processing device, due to the needs of the equipment structure, the reaction gas delivery channel is usually composed of gaps between the parts inside the upper electrode assembly. This structure is widely used in wafer etching, especially wafer edge etching (wafer edge etching) field. Usually, the reaction gas delivery channel of the plasma processing device is inside the upper electrode assembly and above the wafer, and its gas outlet is a gap between two parts of the upper electrode assembly. However, in the actual installation process, there are often some installation errors between parts, and the uniformity of the gap on the entire circumference, that is, the uniformity of the width of the reaction gas delivery channel, cannot be guaranteed to be consistent, resulting in the problem of uneven etching.

The purpose of the present invention is to provide a plasma processing device and a method for manufacturing the gas spray ring, the plasma processing device transports the reaction gas to the inside of the vacuum reaction chamber through the gas spray ring, It uses a part as the gas supply part, and ensures the uniformity of the output of the reaction gas around the wafer through mechanical processing, so as to ensure that the uneven delivery of the reaction gas will not affect the etching effect due to the installation error of the upper electrode assembly, and greatly improves the stability of the plasma processing device.

In order to achieve the above object, the present invention is achieved through the following technical solutions: the present invention provides a plasma processing device, comprising: a vacuum reaction chamber; an upper electrode assembly located at the top of the vacuum reaction chamber; a lower electrode assembly located at the bottom of the vacuum reaction chamber, the lower electrode assembly and the upper electrode assembly are arranged oppositely, the lower electrode assembly includes a bearing surface for carrying wafers; Plasma is generated between the lower electrode assembly and the lower electrode assembly.

Preferably, the reaction gas delivery device is arranged at the bottom of the vacuum reaction chamber.

Preferably, the outlets of the gas supply holes are inclined toward the wafer.

Preferably, the gas supply holes are uniformly or non-uniformly distributed along the circumference of the wafer.

Preferably, the gas shower ring is made of insulating materials.

Preferably, the insulating material includes ceramic or quartz material.

Preferably, the inner wall and/or outlet of the gas supply hole is provided with a plasma corrosion resistant coating.

Preferably, the plasma corrosion-resistant coating material is Teflon coating, yttrium oxide film layer or anodized aluminum oxide layer.

Preferably, the outlet of the gas supply hole is rounded.

2倍的氣體供應孔的直徑。 Preferably, the diameter of the rounded corner structure

2 times the diameter of the gas supply hole.

Preferably, the plasma is used to etch the edge of the wafer.

Preferably, a gas injection hole is provided in the center of the upper electrode assembly for providing non-reactive gas, which forms a protective gas curtain on the central area of the wafer or cleans the central area of the wafer.

Preferably, the present invention provides a method for manufacturing a gas spray ring in a plasma treatment device, comprising: processing a plurality of gas supply holes on the base material of the gas spray ring; coating the gas supply holes with a plasma corrosion-resistant coating from bottom to top by physical vapor deposition; and coating the gas supply holes with a plasma corrosion resistant coating from top to bottom by chemical vapor deposition.

Preferably, the outlets of the gas supply holes are inclined toward the wafer.

Compared with the prior art, the present invention has the following advantages: In the plasma processing device and its method for manufacturing the gas spray ring provided by the present invention, the plasma processing device uses the gas spray ring part to transport the reaction gas to the vacuum reaction chamber, uses a separate part to realize the transport of the reaction gas, ensures the uniformity of the output of the reaction gas in the wafer circumferential direction, ensures that the uneven delivery of the reaction gas due to the installation error of the upper electrode assembly and the like will not affect the etching effect, and greatly improves the use stability of the plasma processing device; The direction of the wafer is inclined, and the gas flow direction of the reaction gas is oblique from bottom to top, which reduces the possibility of particle pollutants falling to the surface of the wafer during the process, which improves the problem of particle pollution and further ensures the environment in the vacuum reaction chamber.

Furthermore, the inner wall and outlet of the gas supply hole are provided with a plasma corrosion-resistant coating, which increases the service life of the gas spray ring. After the plasma treatment device is put into use, the gas spray ring does not need to be replaced frequently to avoid taking up the working machine time of the plasma treatment device.

Furthermore, the exit of the gas supply hole is rounded, which reduces the impact of the reaction gas on the side wall of the exit of the gas supply hole when the reaction gas flows out from the exit of the gas supply hole, improves the fluidity of the reaction gas, avoids the generation of redundant particle pollutants, and ensures the cleaning of the etching environment to achieve the best etching effect.

100: vacuum reaction chamber

101: Reaction chamber body

102: cavity end cover

103: Wafer transfer port

110: Lower electrode assembly

111: lower electrode ring

120: Upper electrode assembly

121: Insulation isolation part

122: Upper electrode ring

123: fumarole

140: gas spray ring

141: gas supply hole

142: rounded corner structure

150: Reaction gas delivery device

W: Wafer

In order to illustrate the technical solution of the present invention more clearly, the accompanying drawings that need to be used in the description will be briefly introduced below. Obviously, the accompanying drawings in the following description are an embodiment of the present invention. For those skilled in the art, without paying creative work, other accompanying drawings can be obtained further according to these accompanying drawings: Fig. 1 is a kind of plasma treatment device of the present invention; Fig. 2 is a schematic diagram of the gas spray ring of the present invention; An enlarged schematic view of region B.

In order to make the purpose, technical solutions and advantages of the embodiments of the present invention more clear, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings in the embodiments of the present invention. It is obvious that the illustrated embodiments are part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without making creative efforts belong to the protection scope of the present invention.

It should be noted that, in this article, the terms "comprising", "comprising", "having" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or terminal equipment comprising a series of elements not only includes those elements, but also further includes other elements not explicitly listed, or further includes elements inherent to such a process, method, article or terminal equipment. Without further limitations, an element qualified by the phrase "comprising..." or "comprising..." does not exclude the further presence of additional elements in the process, method, article or terminal device comprising the element.

It should be noted that all the drawings are in a very simplified form and use imprecise scales, and are only used to facilitate and clearly assist the purpose of illustrating an embodiment of the present invention.

As shown in FIG. 1 , it is a plasma processing device of the present invention. The plasma processing device includes: a vacuum reaction chamber 100, which is surrounded by a reaction chamber body 101 and a chamber end cover 102. A wafer transfer port 103 is provided on the reaction chamber body 101. The wafer transfer port 103 is used to realize the transfer of the wafer W between the inside and outside of the vacuum reaction chamber 100. The vacuum reaction chamber 100 includes a lower electrode assembly 110, which is arranged at the bottom of the vacuum reaction chamber 100. The lower electrode assembly 110 is provided with a carrying surface, and the wafer W to be processed introduced into the vacuum reaction chamber 100 is placed on the carrying surface. The vacuum reaction chamber 100 further includes an upper electrode assembly 120 opposite to the lower electrode assembly 110. The upper electrode assembly 120 is located at the top of the vacuum reaction chamber 100. At least one radio frequency power supply (not shown) is applied to at least one of the lower electrode assembly 110 and the upper electrode assembly 120 through a matching network to dissociate the reaction gas into plasma, so that plasma is generated between the upper electrode assembly 120 and the edge region of the lower electrode assembly 110. The plasma is used to etch the edge of the wafer W. Specifically, the plasma contains a large number of active particles such as electrons, ions, excited atoms, molecules, and free radicals, and the above-mentioned active particles can undergo various physical and/or chemical reactions with the surface of the wafer W to be processed, so that the morphology of the edge of the wafer W to be processed changes, thereby completing the processing of the edge of the wafer W to be processed. A vacuum pump is disposed at the bottom of the vacuum reaction chamber 100 to discharge gaseous waste generated by the reaction.

In this embodiment, the plasma processing device is suitable for the field of wafer W edge etching. During the process of wafer W undergoing plasma etching to form a design pattern, some redundant film layers, such as polysilicon layer, nitride layer, metal layer, etc., will accumulate on the outer edge area of the wafer W and the outer edge area of the back side. These excess film layers may pollute subsequent processes and equipment, so they need to be removed through an edge etching process. During the edge etching process, the reactive gas usually includes etching gas containing fluorine, chlorine, etc., cleaning gas such as oxygen, and other auxiliary etching gases, so as to perform the edge etching process.

As shown in FIG. 1 , the upper electrode assembly 120 includes an insulating spacer 121 and an upper electrode ring 122 . The insulating isolation part 121 is arranged on the bottom of the movable upper electrode assembly 120, and is arranged opposite to the central area of the wafer W. Alternatively, the insulating spacer 121 can be either a layer structure or a bulk structure. The upper electrode ring 122 is disposed around the outer side of the insulating isolation portion 121 , and the upper electrode ring 122 is disposed opposite to the edge region of the wafer W. The lower electrode assembly 110 includes a lower electrode ring 111 . The lower electrode ring 111 is arranged around and below the edge region of the wafer W (the lower electrode ring 111 can also be flat with the lower surface of the wafer W), and the lower electrode ring 111 and the upper electrode ring 122 are oppositely arranged. During the process, plasma is generated between the upper electrode ring 122 and the lower electrode ring 111 to etch the edge of the wafer W.

As shown in conjunction with FIG. 1 , FIG. 2 and FIG. 3 , it is a plasma processing device for processing the edge of a wafer W in this embodiment, which includes a gas shower ring 140 . The gas spray ring 140 is arranged around the outside of the lower electrode assembly 110. The gas spray ring 140 includes a plurality of gas supply holes 141. The gas supply holes 141 are connected to the reaction gas delivery device 150 for delivering the reaction gas to the inside of the vacuum reaction chamber 100 to generate plasma between the upper electrode assembly 120 and the lower electrode assembly 110. In the present invention, the gas spray ring 140 is used as the gas supply part to transport the reaction gas, and the single gas spray ring 140 can ensure the uniformity of its pipeline through mechanical processing, which alleviates the problem of uneven gas output of the reaction gas transported in the circumferential direction, and then ensures the uniformity of gas transport to ensure the effect of etching the edge of the wafer W.

In this embodiment, the gas shower ring 140 is made of insulating materials. The gas shower ring 140 made of insulating materials will not interfere with the plasma environment during the manufacturing process, and will not cause ignition under the influence of plasma or radio frequency. Preferably, the insulating material includes ceramic or quartz material. In this embodiment, the gas shower ring 140 is made of ceramic material, and its raw material is made by sintering, which is cheap and readily available.

The inner wall and outlet of the gas supply hole 141 are provided with a plasma corrosion resistant coating. Preferably, the plasma corrosion-resistant coating material is Teflon coating, yttrium oxide film layer or anodized aluminum oxide layer. During the plasma etching process, the plasma corrosion-resistant coating can reduce the impact of physical bombardment or chemical reaction on the gas shower ring 140 , and reduce the possibility of damage to its surface structure. In addition, the plasma corrosion-resistant coating also prevents the plasma and transported reaction gas from damaging the surface structure of the inner wall and outlet of the gas supply hole 141 of the gas spray ring 140, avoiding the separation of bulk components on the surface and the formation of solid particles from the surface The wafer W is polluted by the substance, which affects the etching effect of the edge of the wafer W. Therefore, the plasma corrosion-resistant coating material of the gas spray ring 140 further increases the service life of the gas spray ring 140, reduces the loss cost of the plasma treatment device, and does not need to frequently replace the gas spray ring 140 after the plasma treatment device is put into use, so as to avoid occupying the working machine time of the plasma treatment device.

In this embodiment, the reactant gas delivery device 150 is disposed at the bottom of the vacuum reaction chamber 100 , and the gas spray ring 140 is disposed around the outer side of the lower electrode assembly 110 , and the reactant gas is delivered without the help of the upper electrode assembly 120 . Whether there is no installation error in the assembly of the parts in the upper electrode assembly 120 does not affect the uniformity of the reaction gas delivery, which improves the stability of the plasma processing device. In addition, the gas spray ring 140 and the reaction gas delivery device 150 are located at the bottom of the vacuum reaction chamber 100 to prevent particle contamination from top to bottom into the vacuum reaction chamber 100, reducing the possibility of particle contamination and helping to ensure an environment for wafer W etching.

Further, as shown in FIG. 4 , the outlets of the gas supply holes 141 of the gas shower ring 140 are inclined to the direction of the wafer W, and the gas flow direction of the reaction gas is oblique from bottom to top. In this embodiment, the outlet of the gas supply hole 141 is located below the wafer W, specifically between the wafer W and the vacuum pump. Even if the surface structure of the gas spray ring 140 is damaged in the plasma environment for a long time, tiny particles are precipitated on the surface. Since the gas flow direction of the reaction gas is from bottom to top, even if there are tiny particles, it is difficult to transport them from bottom to top in the oblique gas supply hole 141 . In addition, since the outlet of the gas supply hole 141 is located between the wafer W and the vacuum pump, if a few particles exit the gas supply hole 141 , the vacuum pump can easily discharge the particles out of the vacuum reaction chamber 100 . Obviously, the outlet position of the gas supply hole 141 is not limited thereto, and in another embodiment, the outlet of the gas supply hole 141 is close to the edge of the wafer W. Referring to FIG.

Preferably, the gas supply holes 141 are uniformly or non-uniformly distributed along the circumference of the wafer W. In this embodiment, the gas supply holes 141 are evenly distributed along the circumference of the wafer W, and the reaction gas is evenly injected into the vacuum reaction chamber 100 through the gas supply holes 141 of the gas spray ring 140 and then evenly distributed in the edge region of the wafer W. domain, so that plasma is formed between the upper electrode assembly 120 and the lower electrode assembly 110 through capacitive coupling. The gas supply holes 141 are uniformly distributed along the circumferential direction to make the reaction gas distribution uniformly around the edge of the wafer W, which is beneficial to ensure the etching effect of the edge of the wafer W.

2倍的氣體供應孔141的直徑。 Further, the outlet of the gas supply hole 141 is a rounded structure 142 (see FIG. 4 ). During the process, the reaction gas enters the vacuum reaction chamber 100 from the reaction gas delivery device 150 through the gas supply hole 141 and the outlet of the gas supply hole 141. The rounded corner structure 142 reduces the impact of the reaction gas on the side wall of the gas supply hole 141 outlet when the reaction gas flows out from the gas supply hole 141 outlet, improves the fluidity of the reaction gas, avoids the generation of redundant particle pollutants, and ensures the cleaning of the etching environment to achieve an optimal etching effect. Further, the exit of the gas supply hole 141 is closer to the wafer W, and the rounded corner structure 142 reduces the contact range or frequency between the side wall of the exit and the reaction gas, and also reduces the possibility of the reaction gas corroding the side wall of the exit, prolongs the service life of the gas spray ring 140, and does not need to replace the gas spray ring 140 multiple times, thereby affecting the experimental work process. Specifically, in this embodiment, the diameter of the rounded corner structure 142

2 times the diameter of the gas supply hole 141 .

In addition, in this embodiment, the center of the upper electrode assembly 120 is provided with an air injection hole 123 . In the edge etching process, the gas injection holes 123 are used to provide non-reactive gas during the process, and the non-reactive gas usually includes buffer gas or cleaning gas. The buffer gas is used to maintain a high pressure above the wafer W when the edge of the wafer W is processed, and to form a protective gas curtain on the central area of the wafer W, so as to prevent the central area of the wafer W from being etched by the plasma environment. During the process, the flow rate or pressure of the non-reactive gas can be adjusted to protect the central area of the wafer W from the influence of the plasma environment. The cleaning gas is used to clean the vacuum reaction chamber 100 when there is no wafer W in the vacuum reaction chamber 100 .

In addition, the present invention further provides a method for manufacturing the gas shower ring 140 in the plasma processing device, the method includes: processing a plurality of gas supply holes 141 on the base material of the gas shower ring 140; The hole 141 is coated with a plasma corrosion resistant coating; the gas supply hole 141 is coated with a plasma corrosion resistant coating from top to bottom by means of chemical vapor deposition (Chemical Vapor Deposition, CVD).

In this embodiment, the base material of the gas shower ring 140 is a ceramic base material, and its raw material is made by sintering. The manufacturing method is simple and the cost is relatively low. The plasma corrosion resistant coating is Y ₂ O ₃ coating to enhance the corrosion resistance of the gas spray ring 140 . In addition, in the present disclosure, the outlet of the gas supply hole 141 is inclined toward the wafer W, so as to realize the supply of reaction gas.

To sum up, in the plasma processing device and its method for manufacturing the gas spray ring 140 provided by the present invention, the plasma processing device combines the upper electrode assembly 120, the lower electrode assembly 110, the gas spray ring 140 and the reaction gas delivery device 150 to realize the delivery of the reaction gas. The installation error of 120 makes the delivery of reaction gas uneven and affects the etching effect, which greatly improves the stability of the plasma processing device.

Further, the outlet of the gas supply hole 141 of the gas spray ring 140 is inclined to the direction of the wafer W, and the reaction gas flow direction is oblique from bottom to top, which reduces the possibility of particle pollutants falling to the surface of the wafer W during the process, improves the problem of particle contamination, and further ensures the environment in the vacuum reaction chamber 100.

Further, the inner wall and outlet of the gas supply hole 141 are provided with a plasma corrosion-resistant coating, which increases the service life of the gas spray ring 140. After the plasma treatment device is put into use, the gas spray ring 140 does not need to be replaced frequently, so as to avoid occupying the working time of the plasma treatment device.

Further, the outlet of the gas supply hole 141 is a rounded corner structure 142, which reduces the impact of the reaction gas on the side wall at the outlet of the gas supply hole 141 when it flows out from the outlet of the gas supply hole 141, improves the fluidity of the reaction gas, avoids the generation of redundant particle pollutants, and ensures the cleaning of the etching environment to achieve an optimal etching effect.

It should be noted that the gas spray ring 140 in the present invention is suitable for both capacitively coupled plasma processing devices and inductively coupled plasma processing devices, that is, the plasma processing device of the present invention can be either a capacitively coupled plasma processing device or an inductively coupled plasma processing device.

Although the content of the present invention has been described in detail through the above preferred embodiments, it should be understood that the above description should not be considered as limiting the present invention. Various modifications and alterations to the present invention will become apparent to those of ordinary skill in the art after reading the above disclosure. Therefore, the protection scope of the present invention should be defined by the appended patent application scope.

100: vacuum reaction chamber

101: Reaction chamber body

102: cavity end cover

103: Wafer transfer port

110: Lower electrode assembly

111: lower electrode ring

120: Upper electrode assembly

121: Insulation isolation part

122: Upper electrode ring

123: fumarole

140: gas spray ring

150: Reaction gas delivery device

W: Wafer

Claims (14)

A plasma processing device, comprising: a vacuum reaction chamber; an upper electrode assembly located at the top of the vacuum reaction chamber; a lower electrode assembly located at the bottom of the vacuum reaction chamber, the lower electrode assembly and the upper electrode assembly are disposed opposite to each other, the lower electrode assembly includes a bearing surface for carrying a wafer; a gas spray ring is arranged around the outer side of the lower electrode assembly, the gas spray ring includes a plurality of gas supply holes, the gas supply holes are connected to a reaction gas delivery device for delivering a reaction gas to the inside of the vacuum reaction chamber, at least one radio frequency power supply applied to at least one of the lower electrode assembly and the upper electrode assembly through a matching network to generate a plasma between the upper electrode assembly and the lower electrode assembly. The plasma processing device according to claim 1, wherein the reactant gas conveying device is arranged at the bottom of the vacuum reaction chamber. The plasma processing apparatus according to claim 1, wherein the outlet of the gas supply hole is inclined toward the wafer. The plasma processing apparatus according to claim 1, wherein the gas supply holes are uniformly or non-uniformly distributed along the circumference of the wafer. The plasma processing device as claimed in claim 1, wherein the gas shower ring is made of an insulating material. The plasma treatment device as described in Claim 5, wherein The insulating material includes ceramic or quartz material. The plasma treatment device as claimed in claim 1, wherein the inner wall and/or outlet of the gas supply hole is provided with a plasma corrosion-resistant coating. The plasma treatment device according to claim 7, wherein the material of the plasma corrosion-resistant coating is Teflon coating, yttrium oxide film layer or anodized aluminum oxide layer. The plasma processing device as claimed in claim 1, wherein the outlet of the gas supply hole is a rounded structure. The plasma processing device as claimed in item 9, wherein the diameter of the rounded corner structure

2 times the diameter of the gas supply hole. The plasma processing device as claimed in claim 1, wherein the plasma is used to etch the edge of the wafer. The plasma processing device as described in Claim 1, wherein a gas injection hole is provided in the center of the upper electrode assembly for providing a non-reactive gas, and the non-reactive gas forms a protective gas curtain or cleans the central area of the wafer. A method for manufacturing a gas spray ring in a plasma processing device as described in any one of claim 1 to claim 12, comprising: processing a plurality of gas supply holes on a base material of a gas spray ring; plating a plasma corrosion-resistant coating on the gas supply holes by physical vapor deposition from bottom to top; The plasma corrosion-resistant coating is plated on the gas supply hole from top to bottom by means of chemical vapor deposition. The manufacturing method of the gas shower ring according to claim 13, wherein the outlet of the gas supply hole is inclined to a wafer direction.